There is something called titer testing, I have not used it but I hear it tells you whether they NEED the shot or not. My vet said it is expensive and poo pooed it, but I hear others do it, so it may depend on the vet. I agree with you, it was the shots......and technically she admitted that by saying she should space them out in the future.
I'd be a bit leery of your vet and her response. She made $ by her own mistake it sounds like. imho. Dogs and cats are over vaccinated I feel. My cat is due for a rabies. He is an inside cat so why should I get it? Talked to the vet and she told me that some kid had a bat fly in the house and bit him and it was rabid. The odds of that happening to my cat and myself are pretty big, and I'll take that "chance". No rabies shot for him.
"People disappoint, dogs never do" - spiritdog
"You MUST be your pets ADVOCATE, if it doesn't feel right walk away." - spiritdog